Building Instructions

Snap the groups of beams together in the order shown
above (each group bottom to top).

10

Use the shortest wire to connect the sound sensor to
port 2 on the NXT, and the medium wire to connect the motor to
port A on the NXT. Route the wires as shown below to keep
them out of the way.

11

Before inserting the candle flame, rotate the handle
on the motor to the vertical position, which should put the lifting arm
on the inside in the high position.

Birthday
Cake Programming

Use the
Birthday_Cake
program for the Birthday Cake. This program takes a lot of memory
in the NXT, so you may need to delete other programs and sounds before
downloading it to the NXT.

How to Use the Birthday Cake

Before running the
program, follow the instructions at the end of the last building
step above to position the motor arm in the correct position to
support the candle flame.

Run the
Birthday_Cake program.
Make sure that the room is quiet so that you can hear the music and
so that the sound sensor does not trigger accidentally.

When the music
finishes, you can blow the candle out.

Before running the
program again, turn the model upside down and remove the candle
flame stick entirely, so that you can position the motor in the
starting position again and re-insert the flame stick.

Challenges

Try adding other
decorations to the cake. Maybe even some motorized decorations
using the other two motors?

As written, the
Birthday_Cake program
makes you wait until the song is over until you can blow out the
flame. For a programming challenge, try modifying the program
to allow the flame to be blown out at any time.

You know those trick
candles that keep re-lighting after you blow them out? With a
little mechanical modification so that the motor arm does not drop
the flame stick entirely, maybe you can modify the candle and the
program to keep re-lighting it after you blow it out, and loop to
let you blow it out multiple times.